Extruding fittings

ABSTRACT

A die, engageable with a clay extruding machine, has a given interior configuration corresponding to the out-side configuration of a pipe fitting. A pair of spaced mandrels are inserted through openings in the die and define a branch opening and a main opening therein. A centrifugal cutting blade is rotatably mounted proximate to the main mandrel and is usable to sever the clay in the die from the extruding machine. A circular cutter is also mounted proximate the die to cut away extruded clay left in the space between the branch opening and the main opening.

O United States Patent [151 3,659,992 Greene May 2, 1972 [54] EXTRUDINGFITTINGS 3,495,308 2/1970 Schulze ..25/39 x [72] Inventor: Bernard A.Greene, Gray, Ga. FOREIGN PATENTS OR APPLICATIONS 1 Assigneel AMSTEDindustries Imrlmmed, 1,191,155 /1970 Great Britain ..25/36 chlcago850,564 9/1970 Canada ..25/30 R [22] Filed: Oct. 7, 1968 PrimaryExaminerJ. Spencer Overholser PP No.2 765,378 Assistant Examiner-Ben D.Tobor Att0rneyWalter L. Schlegel, Jr. and John W. Yakimow [52] US. Cl..425/192, 264/323, 425/97,

425/310, 425/38l 1 ABSTRACT [51] Int. Cl 1 ..B28b 21/52 A die en b gageale with a clay extruding machine, has a g1ven [58] of Search i interiorconfiguration corresponding to the out-side configu- 25/39' 127 I 4 Hration ofa pipe fitting. A pair of spaced mandrels are inserted throughopenings in the die and define a branch opening and a main openingtherein. A centrifugal cutting blade is rotatably [56] References cuedmounted proximate to the main mandrel and is usable to sever UNITEDSTATES PATENTS the clay in the die from the extruding machine. Acircular cutter 1s also mounted proxlmate the die to cut away extrudedgi et clay left in the space between the branch opening and the 1 sonmain 0 enin 3,465,075 9/1969 Siegfreid... ..25/39 X p g 3,487,14012/1969 Laux ..25/30 M X 5 Claims, 3 Drawing Figures f K as 6 25 v .905b 42 .90 112 .50 8 8 I I 1 1 I 9: 85 -l- LP-7 i 1 32 l 9U J91 -2 102 3ii/ ,\'Z/"', L|,"3H r 1 3 8 [1U -'L rr l:i 107 .97 8 48 an 1 in." P-L 9a72 as C 1 1 I i i 1H it I0 12 10 1 i 1 Q. itit 11 104 102 I00 70 10? H8ii Lb 6 M A7 4 91 AN 4% i V I I /n\ 1 /28 fi l SHEET 2 OF 2 EXTRUDINGFITTINGS This invention relates to an extruding apparatus, particularly,an apparatus for extruding pipe fittings out of clay.

The invention finds particular utility in the production of vitrifiedclay fittings used in various piping systems, e.g., sewage and watertransmission. These pipe fittings are commonly formed as a Y or Tconfiguration and are used as a junction for a main pipe line and abranch pipe line.

Prior to this disclosure, pipe fittings were generally constructed intwo pieces, a main piece and a branch piece. The pieces were then handmolded into a unitary fitting. Branch pipes produced by thisconventional process are invariably of less than desired quality. Inaddition, the hand forming process is slow and tedious work requiringconsiderable labor by trained personnel. The joints between the twopieces often crack permitting infiltration and exfiltration of fluids.Sealants have often been applied to these joints to eliminate thecracks. These sealants increase the fittings cost and are often foundunacceptable to the user.

It is therefore an object of this invention to provide a new and novelprocess and apparatus to make pipe fittings.

Another object of this invention is to provide a process and apparatusto produce monolithic pipe fittings that are free of cracks.

Still another object of this invention is to provide a process andapparatus for rapidly and inexpensively producing pipe fittings.

The foregoing and other objects and advantages of the invention willbecome apparent from the following descripu'on and accompanying drawingswherein:

FIG. 1 is a fragmentary front view of a branch pipe extruding apparatusembodying features of the invention;

FIG. 2 is a sectional view taken on line 2-2 of FIG. 1 illustrating theextruding apparatus and a removal table; and

FIG. 3 is a front view of the removal table illustrated in FIG. 2.

Referring now to the drawings, FIG. 1 illustrates an extruding apparatus6 comprising a split extruding die 8 having halves l and 12. A pivotalpin 14 (FIG. 2) projects through lower sections of each half 10 and 12and through a mounting leg 16. The die halves 10 and 12 may be pivotedabout the pin 14 into tight mating engagement as shown by the solidlines in FIG. 1 or pivotally opened along the center line 2-2. Thisengagement and disengagement may be accomplished by arms 18 and 20respectively secured to the halves l0 and 12 along their rearward end 22(FIG. 2). A known hydraulic cylinder 24 may be pivotally connected tothe upper ends of the arms 18 and 20 and used to pivotally open andclose the halves l0 and 12.

The die 8 may be engaged at its rearward end 22 to an extruding head 26(FIG. 2) of a known extruding machine (not shown). Flanges 28 on the endof the head 26 may be gripped by mating grooves 30 on each half 10 and12. The flanges 28 and grooves 30 may be designed to form a tight,interlocking, quick release joint when the halves 10 and 12 are closedby the cylinder 24.

The interior of the die 8 may be any desired configuration. Asillustrated in FIG. 2, the interior of die 8 defines the exteriorsurface of a known Y-branch pipe 31. As illustrated by the dash lines,the pipe 31 may have front and rear openings 32 and 34 and a branchopening 36.

A center mandrel 38 may be secured to a known hydraulic cylinder 40(FIG. 2) and may be used to define the center passage 41 (FIG. 3) thatinterconnects the openings 32 and 34. A front enclosing collar 42 may beconnected to the front end of the mandrel 38. Mating beveled edges 44and 46 respectively located on the halves l0 and 12 and the collar 42may be used to form a tight, quick release joint therebetween. Theseedges 44 and 46 further maintain alignment of the center mandrel 38 inthe die 8. The collar 42 may be designed to define the interior of ashown front lip configuration 48 on a fitting 31.

The collar 42 may be secured to the die 8 by a crosslock 50 connected tothe collar 42 and having opposed fingers 52 (only one shown in FIG. 1).When the collar 42 is moved into engagement with the die 8 the fingers52 of the lock 50 will be at a slight angle away from the horizontal. Anear 54 on one of the fingers 52 moves between two lugs 56 and 58 securedto a reciprocating slide 60 that is actuated by a known hydrauliccylinder 62. Upward movement of the slide 60 in FIG. I forces the lug 56against the ear 54 and rotates the opposed fingers 52 behind opposedwedges 64 (only one shown) that are secured to a frame 66 integrallymounted on the die halves l0 and 12. Interengagement of the wedges 64and the fingers 52 tightly locks the collar 42 to the front of the die8. Downward movement of the slide 60 forces the lug 58 against the ear54 moving the fingers 52 away from the wedges 64 and freeing the collar42 and mandrel 38 for reciprocating movement. It is contemplated thatthis locking and unlocking action may be accomplished in other ways.

The rearward end of the center mandrel 38 may be provided with aresilient mating beveled member 68 (FIG. 2) that is engageable with abeveled collar 70 in the extruding head 26 to form a quick release seal.The beveled members 68 and 70 further aid in maintaining alignment ofthe center mandrel 38 within the die 8.

A branch mandrel 72 (FIG. 2) may be reciprocated by a known hydrauliccylinder 74. As previously described for the center mandrel 38, thebranch mandrel 72 may also have an enclosing collar 75, and a crosslock76 that may be engaged with wedges 77 (FIG. 1) by a slide 78 having lugs80 and 82 and a known hydraulic cylinder 84. The collar 75 and die 8 maybe constructed to form a quick release aligning joint therebetweensimilar to that described for the collar 42. Other means of lockingcollar 75 are contemplated.

The branch mandrel 72 in its engaged position (FIG. 2) may define theinterior of a known lip configuration 86 in the branch of the fitting 31and its distal end 88 may have a deflecting configuration in the fonn ofa cone, spherical segment or the like. It should be noted that the end88 does not contact the center mandrel 38 but remains a given distancefrom that mandrel 38, e.g., one-fourth of an inch, during extrusion ofafitting 31.

In operation, the mandrels 38 and 72 and the interior of the die 8 maybe coated with a releasing agent. The die 8 and mandrels 38 and 72 maythen be assembled and engaged with the head 26 according to methodspreviously described. Clay may then be forced in a known manner underpressure into the extruding head 26 around the bullet shaped nose 90(FIG. 2), between the spider arms 91 and into contact with the annularcone-shaped end 92 of the head 26. The clay then moves over the beveledcollar 70 and the center mandrel 38 of the die 8.

Trapped air in the die ahead of the clay is forced out through issueholes 94 and 96 in the collars 42 and 75. As clay passes around thebranch mandrel 72 it is partially deflected upwardly into the lip 86 bythe coned end 88. As more and more clay is forced into the die 8, allthe spaces of the die are eventually filled, resulting in clay beingforced out of the issue holes 94 and 96.

The presence of the space 97 between the branch mandrel 72 and centermandrel 38 eliminates a clay knitting problem. Intersection of themandrels 38 and 72 would split the clay flow around mandrel 72 requiringthe clay to knit together on the opposite side of mandrel 72 as itproceeds to fill the die 8. Lack of proper knitting creates troublesomecracks in this area. By separating the mandrels 38 and 72 the clay mayflow through this area in an unbroken mass, thus eliminating cracks andresulting in a better, longer lasting monolithic fitting.

The pressure on the clay may be released after a fitting 31 is formedand the front cross lock 50 unlocked by the slide 60 and cylinder 62.The center mandrel 38 may then be moved to the right in FIG. 2 a givendistance, e.g., 1 inch, by cylinder 40.

The cross lock 76 on branch mandrel 72 may be similarly unlocked byslide 78 and cylinder 84. The branch mandrel 72 may then be removed fromthe die 8 by cylinder 74. The cylinder 24 may then be actuated and thehalves 10 and I2 pivoted to an open position.

A known rotating cutter 98 (schematically illustrated) may then be usedto sever the clay at the junction of the die 8 and the head 26. Thiscutter 98 may be actuated by a shaft 100 mounted in bearings 102. Aknown miter gear arrangement 104 may be used to transmit rotationalmovement of a vertical shaft 106 that is actuated by an outside source,e.g., a motor (not shown), to the horizontal shaft 100 and cutter 98.This rotational movement forces the cutting blades 107 radially outwardby centrifugal and frictional forces, thereby severing the clay from thehead 26. The rearward end of a fitting 31 may also be severed in otherways, e.g., by opening the halves l and 12 and drawing a wire throughthe clay at the desired point.

Once the clay is severed, the formed fitting 31 may be removed from thedie 8. As shown by the dash lines in FIG. 2, this removal may beaccomplished among other ways as follows.

A table 108 may be located in front of the die 8 (F168. 2 and 3). Thistable 108 may be pivotally connected by a bearing block 1 secured to abase 112 at one end and vertically actuated for reciprocating movementby a known hydraulic cylinder 114 at the other end proximate the die 8.A pipe fitting transporting cart 116 may be mounted on wheels 118rotatably engaged with the table 108. A stop 120 may be used to retainthe cart 116 on the table 108 when the table is lowered by the cylinder114.

In removal, the table 108 is lowered. The center mandrel 38 and theengaged pipe fitting 31, which has been severed from head 26, may bemoved away from the open die 8 over the table 108 by cylinder 40. Thetable 108 may then be raised, moving the cart 116 into contact with thefitting 31. The cart 116 may be designed to cradle the fitting 31 andthe table 108 may have a front stopper plate 122 that is engageable witha portion of the front lip 48 of the fitting 31. After contact is madebetween the lip 48 and plate 122, the center mandrel 38 may be extractedfrom the fitting 31 by further movement of cylinder 40 as shown in FIG.2.

The cart 116 and fitting 31 may be rolled to a second location on thetable 108. A non-rotating thin edged metal pipe 124 (schematicallyillustrated) may then be inserted into the branch opening 36. Thispipe-type cutter is usable to cut away the excess clay that was extrudedin space 97 between the branch mandrel 72 and the center mandrel 38.Actuation of the cutter 124 may be by any known linear motion device(not shown). It should be noted that the branch cutting step may also beperformed at the extrusion location by a similar apparatus. The cutter124 and the mandrel 72 could be mounted on a common swivel-type platformand alternately swung into and out of alignment with the branch opening36 of the fitting 31. It is further contemplated that this branchcutting step may be performed by hand or in other material removingways.

Once the excess clay in space 97 is removed, the fitting 31 may be firedin a periodic or tunnel kiln (not shown) in a known manner.

Although the invention is illustrated as a method and apparatus forextruding Y-branch pipes it is to be understood that tees andmultibranch pipes may also be made in a similar manner.

It is to be further understood that the foregoing description and theaccompanying drawings have been given only by way of illustration andexample. Changes in form of the elements, rearrangement of parts, andsubstitution of equivalent elements, which will be obvious to thoseskilled in the art, are contemplated as within the scope of the presentinvention which is limited only by the claims which follow.

1 claim:

1. An apparatus for extruding pipe fittings from a moldable materialcomprising: a die having a cavity therein and openings communicatingwith said cavity and the exterior of said die, said openings including afront and rear opening in substantial alignment and a side opening; amain mandrel which is stationary during extrusion of a pipe fittinglocated in said cavity, said main mandrel pro'ects through said frontand rear openings and has a collar whic is stationary during extrusionof a pipe fitting enclosing said front opening; a secondary mandrelwhich is stationary during extrusion of a pipe fitting located in saidcavity and spaced from said main mandrel, said secondary mandrelprojects through said side opening and has a collar which is stationaryduring extrusion of a pipe fitting enclosing said side opening; andextruding means to force said moldable material into said cavity throughsaid rear opening around and between said main mandrel and saidsecondary mandrel until said material configures to the shape of saidcavity and said mandrels.

2. The apparatus set out in claim 1 wherein: said extruding meansincludes an extruding head having an opening therein and a centersection spaced inwardly of said head opening, said head opening and saidcenter section defining a passage therebetween; said die releasablyengages said extruding head; said cavity is in communication with saidpassage in said extruding head; said main mandrel releasably engagessaid center section; and said moldable material is forced through saidpassage into said cavity.

3. The apparatus set out in claim 2 wherein: cutting means is locatedinwardly of said main mandrel proximate said center section, saidcutting means including blade means radially extendable to sever themoldable material in said cavity proximate said center section when saidmain mandrel is spaced from said center section.

4. The apparatus set out in claim 1, 2, or 3 wherein: said die includessections mounted for engagement along a longitudinal line; said cavityis substantially symmetrical about said longitudinal line; said mainmandrel is substantially symmetrical about said longitudinal line; andsaid secondary mandrel is substantially symmetrical about saidlongitudinal line.

5. The apparatus set out in claim 1, 2, or 3 wherein: said secondarymandrel has a central axis and an end having a point proximate said mainmandrel, said end being substantially symmetrical about said centralaxis and converging toward said point.

1. An apparatus for extruding pipe fittings from a moldable materialcomprising: a die having a cavity therein and openings communicatingwith said cavity and the exterior of said die, said openings including afront and rear opening in substantial alignment and a side opening; amain mandrel which is stationary during extrusion of a pipe fittinglocated in said cavity, said main mandrel projects through said frontand rear openings and has a collar which is stationary during extrusionof a pipe fitting enclosing said front opening; a secondary mandrelwhich is stationary during extrusion of a pipe fitting located in saidcavity and spaced from said main mandrel, said secondary mandrelprojects through said side opening and has a collar which is stationaryduring extrusion of a pipe fitting enclosing said side opening; andextruding means to force said moldable material into said cavity throughsaid rear opening around and between said main mandrel and saidsecondary mandrel until said material configures to the shape of saidcavity and said mandrels.
 2. The apparatus set out in claim 1 wherein:said extruding means includes an extruding head having an openingtherein and a center section spaced inwardly of said head opening, saidhead opening and said center section defining a passage therebetween;said die releasably engages said extruding head; said cavity is incommunication with said passage in said extruding head; said mainmandrel releasably engages said center section; and said moldablematerial is forced through said passage into said cavity.
 3. Theapparatus set out in claim 2 wherein: cutting means is located inwardlyof said main mandrel proximate said center section, said cutting meansincluding blade means radially extendable to sever the moldable materialin said cavity proximate said center section when said main mandrel isspaced from said center section.
 4. The apparatus set out in claim 1, 2,or 3 wherein: said die includes sections mounted for engagement along alongitudinal line; said cavity is substantially symmetrical about saidlongitudinal line; said main mandrel is substantially symmetrical aboutsaid longitudinal line; and said secondary mandrel is substantiallysymmetrical about said longitudinal line.
 5. The apparatus set out inclaim 1, 2, or 3 wherein: said secondary mandrel has a central axis andan end having a point proximate said main mandrel, said end beingsubstantially symmetrical about said central axis and converging towardsaid point.